How To Close My Above Ground Pool For The Winter
Properly winterizing your above ground pool requires balancing water chemistry, dropping the water level below the skimmer, and installing a heavy-duty winter cover to prevent algae growth and structural freeze damage. Executing these precise steps before the first hard freeze protects your liner, plumbing, and structural walls from costly off-season deterioration.
Essential Equipment, Chemicals, and Pre-Winter Planning
Closing an above ground pool successfully requires gathering the correct materials before you begin the labor-intensive physical steps. Attempting to winterize a pool with inadequate winterization chemicals or a degraded cover often results in severe spring algae blooms, green water, and frozen plumbing lines.
- Essential Gear and Tools: Pool cover pump, standard garden hose, leaf net, telescopic pole, chemical test kit, winterizing plug, Teflon tape, and a heavy-duty above ground winter cover with a winch and cable kit.
- Mandatory Winterizing Chemicals: pH increaser or decreaser, total alkalinity increaser, calcium hardness increaser, non-chlorine shock, long-lasting winter algaecide, and slow-dissolving winterizing floater or slow-release enzyme packets.
- Environmental Prerequisites: Begin the closing process when ambient water temperatures consistently drop below 65 degrees Fahrenheit. This temperature threshold slows algae reproduction and bacterial growth, keeping the chemical balance stable throughout the winter months.
- Budget and Time Benchmarks: Expect the physical process to take between 3 and 5 hours of labor, with a materials budget ranging from one hundred to three hundred dollars depending on whether you need a replacement winter cover or new skimmer plates.
Step-by-Step Above Ground Pool Winterization Process
Step 1: Deep Clean and Balance Water Chemistry
Before altering the water level or adding winter chemicals, thoroughly brush the pool walls and floor to dislodge embedded debris and algae spores. Vacuum the entire pool floor to waste, ensuring no organic matter remains to decompose under the winter cover. Test the water chemistry and adjust the parameters to ideal ranges: pH between 7.2 and 7.6, total alkalinity between 80 and 120 ppm, and calcium hardness between 200 and 400 ppm. Balancing these levels prevents metal corrosion, liner staining, and scaling while the pool sits dormant.
Step 2: Shock and Add Winter Algaecide
Broadcast a strong dose of non-chlorine shock or liquid chlorine across the surface of the pool with the pump running continuously for at least 8 to 12 hours to distribute the sanitizer evenly. After the free chlorine level drops back to normal parameters, pour in a concentrated winter algaecide designed to prevent green, black, and mustard algae growth over several months.
Pro-Tip: Never mix different pool chemicals together in a bucket, as hazardous chemical reactions can occur. Always add chemicals directly to the circulating pool water with the pump running.
Step 3: Lower the Water Level and Drain Plumbing
Lower the water level in your above ground pool based on the specific type of skimmer and return setup you utilize. For standard skimmers, drop the water level approximately 4 to 6 inches below the skimmer mouth to prevent freezing water from cracking the plastic housing. If you use an A-B-Plast style skimmer plate or an expandable winter skimmer cover, you may only need to drop the water slightly or keep it at normal operating levels. Disconnect the hoses running between the pool wall, pump, and filter system. Completely drain the pump, filter tank, and chlorinator, storing them indoors in a frost-free area like a garage or basement to prevent freeze-cracking.
Step 4: Plug Return Jets and Protect Skimmers
Insert a rubber expansion winter plug coated with Teflon tape into the return jet from the inside of the pool to block water from escaping into the plumbing lines. For extra protection against sub-zero temperatures, blow out the underground or above-ground return lines with a shop vacuum and add pool antifreeze specifically rated for swimming pools if your configuration requires it. Seal the skimmer mouth using a dedicated skimmer cover plate, or place a skimmer guard bottle inside the skimmer to absorb the expansion pressure of freezing ice.
Step 5: Install the Winter Cover and Air Pillow
Place a heavy-duty air pillow in the exact center of the pool surface and inflate it to approximately 60 to 70 percent capacity. The air pillow absorbs the immense lateral pressure of expanding surface ice, protecting your pool walls from inward buckling. Drape the heavy-duty winter cover evenly over the pool and the inflated air pillow, ensuring excess material hangs equally over the pool perimeter. Secure the cover tightly by threading the vinyl-coated steel cable through the eyelets and cranking the metal winch down firmly.
Warning: Never over-inflate the winter air pillow. Freezing ice compresses the pillow, and an overly rigid pillow can push the winter cover off the top rail during severe winter storms.
How To Close An Intex Above-Ground Pool For The Winter — Peony Street
Technical Parameters of Winterization Chemicals
| Chemical Agent | Target Range / Dosage | Primary Function | Failure Risk if Omitted |
|---|---|---|---|
| Non-Chlorine Shock | 1 lb per 10,000 gallons | Oxidizes organic contaminants | Rapid organic decay and cloudy water |
| Winter Algaecide | Manufacturer label rate | Inhibits spore reproduction | Severe green swamp conditions by spring |
| pH Adjuster | 7.2 to 7.6 ppm | Stabilizes water balance | Liner staining, wrinkling, and corrosion |
| Pool Antifreeze | 1 to 2 quarts per line | Prevents underground pipe bursting | Cracked PVC plumbing and fittings |
Common Site Failures and Field Fixes
- Scenario: Winter cover sinks into the pool during heavy rain or snow.
- Root Cause: The winch cable was left too loose, or melting snow created excessive central weight that pulled the cover past the top rail.
- Actionable Fix: Use a submersible cover pump to drain accumulated water off the top of the cover, adjust the winch cable to a tighter tension, and secure cover clips around the top ledges to prevent slippage.
- Scenario: Skimmer housing cracks during a deep freeze.
- Root Cause: The water level was left too high, or rainwater filled the skimmer box and froze without an expansion bottle inside.
- Actionable Fix: Drain the pool water below the skimmer level immediately upon noticing spring leaks, remove the damaged skimmer assembly, and replace the plastic housing and gaskets before opening.
- Scenario: Water turns neon green and foul-smelling by early spring.
- Root Cause: Inadequate algaecide dosage or a premature breakdown of sanitizer due to high organic loads introduced before closing.
- Actionable Fix: Shock the pool heavily with liquid chlorine, run a portable submersible pump with a filter bag to clear large debris, and apply a flocculant to drop suspended organic matter to the floor for vacuuming.
Frequently Asked Questions
When is the best time to close my above ground pool?
You should close your pool when daytime temperatures consistently hover below 60 degrees Fahrenheit and nighttime temperatures approach freezing. Closing too early while water is warm triggers algae blooms, while closing too late risks sudden frost damage to exposed plumbing lines.
Do I need to drain my above ground pool completely for the winter?
Never drain an above ground pool completely for the winter. The outward pressure of the water inside the pool counters the inward pressure of frozen ground and snow surrounding the structure, keeping the vinyl liner stretched tightly and preventing wall collapse.
How do I keep water off my winter pool cover?
Utilize an electric automatic or manual submersible cover pump placed in the lowest point of the sagging cover to remove rainwater and melting snow throughout the winter and early spring. Keeping excess weight off the cover prevents it from collapsing into the pool water below.
Can I leave my pool pump and filter outside during freezing weather?
Leaving water inside pool pumps, sand filters, or cartridge filters during freezing temperatures will crack plastic housings and manifolds. Always disconnect hoses, drain all residual water from the entire filtration system, and store the equipment in a dry, frost-free shed or garage.
What causes an air pillow to deflate over the winter?
Air pillows often deflate due to faulty inflation valves, pinhole punctures from sharp ice edges, or extreme temperature drops that cause air volume contraction. Check the valve seal carefully before inflation and replace old, brittle pillows every two to three seasons.
Take control of your seasonal pool maintenance today by gathering your winterizing supplies and following this proven step-by-step protocol to ensure a crystal-clear opening next season.
